With the increased penetration and use of cellular communication devices and due to various regulations, these devices are designed to transmit information at or below a predetermined power level. Due to several factors including frequency changes, temperature swings, component selection and tolerances, the actual output power can vary substantially. Consequently, the mobile phone should have a mechanism for controlling the transmitted output power and to verify that it will not be higher than the maximal output power level as allowed by the specific transmission standard. This method for regulating the transmitted output power may be viewed as a transmit automatic gain control (TX-AGC). In addition to transmitting the information at the maximum allowable power level, battery life conservation and current consumption are typically parameters in the design of the automatic gain control.
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